1、SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirelyvoluntary, and its applicability and suitability for any particular use, including any patent infringement arising therefro
2、m, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions.Copyright 1999 Society of Automotive Engineers, Inc.All rights reserved. Printed in U.S.
3、A.QUESTIONS REGARDING THIS DOCUMENT: (724) 772-7121 FAX: (724) 776-0243TO PLACE A DOCUMENT ORDER: (724) 776-4970 FAX: (724) 776-0790SAE WEB ADDRESS: http:/www.sae.org400 Commonwealth Drive, Warrendale, PA 15096-0001AEROSPACE MATERIAL SPECIFICATIONAMS-I-538Issued JUN 1999Insulation, Electrical, Paste
4、d-MicaFSC 5640NOTICEThis document has been taken directly from U.S. Military Specification HH-I-538b and contains only minor editorial and format changes required to bring it into conformance with the publishing requirements of SAE technical standards. The initial release of this document is intende
5、d to replace HH-I-538b. Any part numbers established by the original specification remain unchanged.The original Military Specification was adopted as an SAE standard under the provisions of the SAE Technical Standards Board (TSB) Rules and Regulations (TSB 001) pertaining to accelerated adoption of
6、 government specifications and standards. TSB rules provide for (a) the publication of portions of unrevised government specifications and standards without consensus voting at the SAE Committee level, and (b) the use of the existing government specification or standard format.Under Department of De
7、fense policies and procedures, any qualification requirements and associated qualified products lists are mandatory for DOD contracts. Any requirement relating to qualified products lists (QPLs) has not been adopted by SAE and is not part of this SAE technical document.COPYRIGHT SAE International (S
8、ociety of Automotive Engineers, Inc)Licensed by Information Handling ServicesAMS-I-538 SAE AMS-I-538- 2 -1. SCOPE AND CLASSIFICATION:1.1 Scope: This specification covers pasted-mica electrical insulation for molded armature slot bases, commutator insulation, shells, heating elements, and other simil
9、ar insulating purposes.1.2 Classification: 1.2.1 Types and forms: Pasted-mica electrical insulation furnished under this specification shall be of the following types and forms, as specified (see 6.1).Type PMR - Pasted mica, rigidForm S - Sheets (plates)Type PMM - Pasted mica, moldableForm R - Rings
10、Form S - Sheets (plates)Form T - TubesForm X - Special shapesType PMF - Pasted mica, flexibleForm S - Sheets (plates)Type PMH - Pasted mica, heat-resistantForm S - Sheets (plates)2. APPLICABLE DOCUMENTS: The following publications, of the issue in effect on date of invitation for bids or request for
11、 proposal, form a part of this specification to the extent specified herein.2.1 U.S. Government Publications: Available from DODSSP, Subscription Services Desk, Building 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094.PPP-B-585 Boxes, Wood, WireboundPPP-B-601 Boxes, Wood, Cleated-PlywoodPPP-B-62
12、1 Boxes, Wood, Nailed and Lock-CornerPPP-B-636 Box, FiberboardPPP-T-60 Tape, Pressure Sensitive Adhesive, WaterproofFED-STD-102 Preservation, Packaging and Packing LevelsFED-STD-123 Marking for Domestic Shipment, (Civilian Agencies)MIL-A-101 Adhesive, Water-Resistant, For Sealing Fiberboard BoxesCOP
13、YRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling ServicesAMS-I-538 SAE AMS-I-538- 3 -2.1 (Continued):MIL-STD-105 Sampling Procedures and Tables for Inspection by AttributesMIL-STD-129 Marking for Shipment and Storage2.2 American Standards Association, I
14、nc. Publications: Available from the American Standards Association, Inc., 10 East 40th Street, New York 16, NY.C68.1 Measurement of Test Voltage in Dielectric Tests2.3 ASTM Publications: Available from ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959.ASTM D 2131-62 Specification for Na
15、tural Muscovite Mica Splittings2.4 National Electrical Manufacturers Association Publications: Available from the National Electrical Manufacturers Association, 155 East 44th Street, New York 17, NY.ME1-1956 Manufactured Electrical Mica3. RREQUIREMENTS: 3.1 Composition: 3.1.1 Pasted-mica electrical
16、insulation shall consist of, or contain, muscovite mica conforming to the requirements of ASTM D 2131-62 unless phlogopite mica is specifically required. When use of phlogopite mica is required, the electrical insulation, unless otherwise specified, shall conform to the minimum standards of performa
17、nce prescribed hereinafter, for the corresponding item employing muscovite mica.3.1.2 The mica shall not be calcined or treated in any manner which will adversely affect its suitability for the purpose intended.3.2 Construction: 3.2.1 General: The pasted mica shall consist of layers of overlapping m
18、ica splittings held together by a suitable binding material. The finished surface shall be reasonably smooth and free from excess binder and loosened mica, and shall not be tacky.COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling ServicesAMS-I-538 SAE
19、AMS-I-538- 4 -3.2.2 Mica splittings: 3.2.2.1 Mica splittings used for pasted-mica electrical insulation shall be sound, clean, and free from mineral inclusions.3.2.2.2 The size and thickness range of mica splittings used in the specified types of pasted-mica electrical insulation shall conform to th
20、e requirements shown in table I and ASTM D2131-62 for the applicable grade.TABLE I - Size and thickness ranges for mica splittings3.2.3 Binding material: The binding material for pasted mica electrical insulation shall be a high-quality insulating material free from any deleterious ingredients which
21、 may adversely affect the physical and electrical properties of the combination of mica and binder. The binding material shall be uniformly distributed and the proportion of binding material to mica shall be as low as is compatible with requisite mechanical and electrical properties hereinafter spec
22、ified. It shall be chemically inert with respect to materials normally used in electrical equipment, under conditions of rated operating temperature and presence of humid salt atmosphere.3.3 Type PMR, pasted mica, rigid: 3.3.1 General: Unless otherwise specified, type PMR mica shall be furnished in
23、form S, sheets (plates).3.3.2 Uniformity and density: The mica splittings and the binding material shall be as uniformly distributed as practicable, with neither high spots that have received excessive pressure nor low spots or pockets that are filled with binder. The density uniformity shall be tak
24、en as an index of the material uniformity and absence of air pockets. This density shall average not less than 0.088 pound per cubic inch per lot and shall be not less than 0.086 pound per cubic inch for each sheet.3.3.3 Mica content: The mica content shall be not less than 93 percent by weight.3.3.
25、4 Binder-to-mica adhesion: The binding material shall provide satisfactory adhesion between the mica splittings. Satisfactory adhesion is indicated by the absence of delamination and surface cracking when sheets (plates) are bent to the radii specified in 4.5.4.COPYRIGHT SAE International (Society o
26、f Automotive Engineers, Inc)Licensed by Information Handling ServicesAMS-I-538 SAE AMS-I-538- 5 -3.3.5 Compressibility, exudation, and slippage: The thickness of type PMR mica shall not decrease by more than 6 percent and there shall be only slight amounts of either splittings displacement or binder
27、 exudation when the material is compressed under 2,500 pounds per square inch at a temperature of 150 degrees C. (302 degrees F.) as described in 4.5.5.1.3.3.6 Dielectric strength: The dielectric qualities of type PMR electrical insulation shall be expressed in terms of short-time and step-by-step d
28、ielectric break-down values. For all thicknesses, rigid mica sheets (plates) shall have average short-time dielectric strength of at least 600 volts per mil of specified thickness, and at least 390 volts per mil step by step.3.3.7 Dimensions and tolerances: Size of sheets (plates) furnished shall be
29、 18 by 36 inches or 25 by 37 inches, as specified. A tolerance of plus or minus 1/2 inch will be allowed. The sheets (plates) shall be furnished in standard thickness of 0.020, 0.025, 0.030, 0.0325, 0.035, 0.040, 0.045, and 0.050 inch, as specified. The thickness shall not vary by more than plus or
30、minus 0.002 inch from the nominal value, and the average of 10 measurements shall be within plus or minus 0.001 inch of the specified thickness.3.4 Type PMM, pasted mica, moldable: 3.4.1 Form R, rings: 3.4.1.1 General: The molded mica rings shall be made in accordance with an approved design or dime
31、nsional drawing furnished by the procuring agency. The rings may be either press-molded or form-molded, unless one is specified in the contract or order.3.4.1.2 Mica content: The mica content of press molded rings, which, normally are 6 inches or less in diameter, shall be not less than 80 percent b
32、y weight. The mica content of form-molded rings, either complete or in sectional condition, shall be not less than 82 percent by weight, unless otherwise specified.3.4.1.3 Dielectric strength: The dielectric strength for type PMM molded mica rings shall be as specified. Where particular values are n
33、ot specified, minimum dielectric strength for type PMM mold rings shall be 125 volts per mil short-time and 75 volts per mil step-by-step.3.4.1.4 Dimensions and tolerances: The dimensions and tolerances of molded mica rings shall be as specified on the dimensional drawing. The wall thickness shall n
34、ot vary from those specified by more than the values shown in table II.COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling ServicesAMS-I-538 SAE AMS-I-538- 6 -TABLE II - tolerance for wall thickness, typePMM, form R3.4.2 Form S, sheets (plates): 3.4.2.1
35、 Mica content: The mica content shall be not less than 82 percent by weight.3.4.2.2 Moldability: When uniformly heated to a temperature of 135 degrees C. (275 degrees F.) sheets (plates) of moldable mica shall be capable of being readily molded to the simple test form as described in 4.5.6, without
36、chipping, flaking, cracking, or breaking. The molded form shall be retained upon cooling to room temperature.3.4.2.3 Dielectric strength: Sheets (plates) of moldable mica shall have a dielectric strength in accordance with table III.TABLE III. Dielectric strength, according tothickness, type PMM, fo
37、rm S3.4.2.4 Dimensions and tolerances: Size of sheets (plates) furnished shall be 18 by 36 inches or 25 by 37 inches, as specified. A tolerance of plus or minus 1/2 inch will be allowed. The sheets (plates) shall be furnished in thicknesses of 0.005, 0.010, 0.015, 0.020, 0.025, 0.030, 0.0325, 0.035,
38、 0.040, 0.050, and 0.0625 inch as specified.3.4.2.4.1 Milled material: Material milled to thicknesses of 0.020 to 0.050 inch, shall not vary by more than plus or minus 0.003 inch from the nominal value, and the average shall be within plus or minus 0.002 inch of the specified thickness; for material
39、 milled to thicknesses over 0.050 inch, the corresponding values shall be plus or minus 6 percent and plus or minus 4 percent, respectively.COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling ServicesAMS-I-538 SAE AMS-I-538- 7 -3.4.2.4.2 Unmilled materi
40、al: The average thickness of unmilled or rough milled material in thickness less than 0.015 inch shall be within plus or minus .003 inch of the specified thickness. Unmilled or rough milled material in thickness from 0.015 to 0.063 inch, shall not vary by more than plus or minus 0.008 inch from the
41、nominal value, and the average shall be within plus or minus 0.005 inch of the specified thickness.3.4.3 Form T, tubing: 3.4.3.1 General: Pasted-mica tubing of all cross-sectional shapes shall be included under form T; however, unless otherwise specified, tubing of circular cross-section shall be fu
42、rnished. Unless otherwise specified, a thin protective covering of paper shall be applied to the outside of the tubing 1/4 inch in inside diameter and over and may be applied to the smaller sizes.3.4.3.2 Mica content: The mica content shall be not less than 80 percent by weight for inside diameters
43、greater than 1/4 inch. For inside diameters of 1/4 inch or less, the mica content shall be not less than 75 percent by weight. For tubing of other than circular cross-section, the mica content shall be not less than 70 percent by weight. Where a protective covering is supplied, the minimum mica cont
44、ent of the tubing may be 5 percent less, on the total weight basis.3.4.3.3 Dielectric strength: The dielectric qualities required of mica tubing shall be expressed in terms of average dielectric breakdown values. For wall thicknesses of 1/8 inch or less, mica tubing of circular cross-section shall h
45、ave a dielectric strength of 200 volts per mil of specified thickness step-by-step and 300 volts per mil short-time. For shapes other than circular cross-section the dielectric strength shall be as specified.3.4.3.4 Dimensions and tolerances: Unless otherwise specified, mica tubing shall be furnishe
46、d in the standard dimensions shown in table IV, as required.TABLE IV - Standard dimensions, type PMM,form TA tolerance of plus or minus 1/2 inch will be allowed in the specified length of the tubing. The average inside diameter of molded mica tubing shall be within plus 0.005 or minus 0.003 inch of
47、the specified diameter. The average outside diameter of molded mica tubing shall be within plus or minus 0.010 inch of the specified diameter.COPYRIGHT SAE International (Society of Automotive Engineers, Inc)Licensed by Information Handling ServicesAMS-I-538 SAE AMS-I-538- 8 -3.4.4 Form X, special s
48、hapes: 3.4.4.1 General: Molded and formed sections, such as armature slot bases, shields, and shells, as well as any special sections that may be specified, shall comprise form X. These items shall be made in accordance with an approved design or dimensional drawing furnished by the procuring agency
49、.3.4.4.2 Mica content: The mica content shall be not less than 80 percent by weight for simple shapes and 75 percent for small and intricate shapes, unless otherwise specified.3.4.4.3 Dielectric strength: Molded and formed sections shall satisfy the dielectric strength requirements as specified for type PMM, form R. (See 3.4.1.3.)3.4.4.4 Dimensions and tolerances: The dimensions and tolerances of molded and formed sections shall be as specified on the dimensional drawing.3.5 Type PMF, pasted mica, flexible: 3.5.1 General: Type PMF electrical insulation shall be suitable for forming into or
